Generally speaking, contemporary handheld and mobile computing devices (“mobile devices”) may be operable in uses relating to Automatic Identification & Data Capture (AIDC). For example, a portable data terminal (PDT) or other mobile device may be operable for scanning radio frequency identification (RFID) tags and/or graphic data patterns such as bar codes. The AIDC is used in logistics, shipping, cargo handling and transport, commerce, security, and various other endeavors.
In view of the various endeavors in which it is used, the mobile devices may be operable for performing the AIDC in more than one environment. For example, the mobile devices may be tasked to operate in relation to the AIDC within an indoor use environment, or within an outdoor use environment. Ambient characteristics of the outdoor environment, such as an ambient lighting intensity level, may contrast significantly from the ambient characteristics of the outdoor use environment.
The performance of an AIDC operation may involve aiming the mobile device at a scan target. The aiming allows the mobile device to be aligned for directing illuminating and/or triggering energy at the scan target. The aiming also allows the mobile device to be aligned for a sensing a reflection of the illumination (e.g., in scanning barcodes), or a responsively triggered emission (e.g., in scanning RFID tags). The aiming may be performed by a laser associated with the mobile device.
An operator may aim the mobile device by directing a visible linear light beam emitted by the laser at the scan target. The mobile device is aligned with the scan target based on the operator's observation of a reflection of the illumination of the scan target by the laser beam directed thereto. The scan of the target by the mobile device may be triggered upon observing the reflection of the laser beam directed thereto. The observation of the reflection of the laser beam from the target relates to its perceptibility.
The perceptibility of the laser beam reflection from the scan target to the operator relates to multiple factors. Assuming operators to have visual acuity and ocular health sufficient to sustain their related occupational activity, the visibility factors include the brightness of the laser beam, the reflectivity of a surface of the scan target, and the brightness of ambient lighting in which the aiming is performed. The ambient lighting brightness relates to the use environment.
Reflections of laser beams emitted at a given power intensity level over one or more visible wavelengths, from targets with similar surface reflectance values, may be more perceivable by the operators when observed under lower ambient lighting intensity levels than when observed under higher ambient lighting intensity levels. Aiming the mobile device with the laser within the indoor use environment may sometimes thus be easier, more efficient, or quicker than with outdoor uses.
A laser associated with the mobile device may illuminate the scan target at a power intensity level sufficient perceptibly for aiming the devices within the relatively low ambient lighting intensity levels typically characterizing indoor use environments. Target illumination sufficient for efficient aiming at higher ambient lighting intensity levels, for example, characterizing daytime outdoor use environments, may be provided by lasers with a significantly higher power intensity levels. The higher power lasers, however, may present optical radiation hazards to the operator and others when used to aim the mobile devices in the indoor use environments.
It could be useful, therefore, to conduct AIDC operations over scan targets efficiently mobile devices in various use environments. It could also thus be useful, in relation to the AIDC operations, to aim the mobile devices with a laser in each of the various use environments, whether indoor or outdoor, and under differing ambient lighting conditions associated each therewith. Further, it could be useful to provide for the perceptibility of the laser beam, with which the mobile device is aimed in relation to the AIDC operations, safely.